What’s that tag for?
Why Scrapie Ear Tags Are So Important
Any time you peruse a livestock supply catalog, you can find a variety of ear tags. Any color your heart could desire, with various shapes and sizes, and room for different types of information. With so many options, the choices are difficult. However, if you plan on selling any of your goats or moving them across state lines, the scrapie identification number must be on the ear tag. A scrapie identification number is a government-approved official form of identification that links an animal permanently to your herd.
So, what is scrapie? Scrapie is a fatal neurologic disease of sheep and goats known as a transmissible spongiform encephalopathy, or TSE. Another well-known TSE of similar concern is bovine spongiform encephalopathy or mad cow disease. In goats and sheep, small protein particles, or prions, are transmitted from animal to animal, commonly infecting animals as kids or adults. Even animals with no signs of the disease can still transmit it to others. The disease symptoms do not manifest until several years after infection, when animals can show severe neurologic signs such as tremors, aggression, obsessive itching, “star-gazing,” and death. As the disease transmits through a herd, animals can begin showing symptoms at a younger age, resulting in significant losses. Because the disease does not appear until much after infection, preventing its entrance into your herd is preferable to discovering its presence.
After discovering scrapie, the USDA implemented the National Scrapie Eradication Program. This program utilizes tracking and testing of animals to locate infected herds and flocks and eliminate the disease. This program involves the official identification of sheep and goats with specific tags. Scrapie tags are tamper-resistant, officially approved by the USDA, and have the owner’s flock ID number included on the tag. A flock ID number is issued to producers by the USDA. As part of the eradication program, the USDA requires official identification of all sheep and goats that leave an owner’s flock. There are a few exceptions. Notably, those include animals under 18 months of age heading for slaughter and castrated animals under 18 months of age. A goat herd with a flock ID and appropriately tagged animals ensures that they can legally be sold or moved. These tags are also helpful for identification purposes, as each tag number is unique. Depending upon the type of tag chosen, further information can also be added, such as a phone number or farm name. These tags ensure that a herd is compliant with USDA regulations and can be helpful for identification and record-keeping purposes.
The other aspect of the National Scrapie Eradication Program is testing. In 2001, the program began testing mature sheep and goats at slaughter. This testing has helped reduce the national incidence of scrapie by over 99%. However, there is still scrapie present in the sheep and goat populations. In addition to government-performed testing at slaughter, animals that pass on farm, especially those that display neurologic signs before passing, can be sent to a government-approved lab for testing. If an adult goat dies on the farm, contact your herd veterinarian to assess if scrapie testing is indicated. Continued testing can further reduce the incidence of disease nationally.
The USDA recognizes that genes make sheep and goats more resistant to scrapie. While the USDA does not officially recognize these tests as part of the national program, it is highly encouraged to begin testing breeding animals for markers of scrapie resistance and breed only resistant ones. Genetic testing performed in Europe has indicated that goats carrying alleles S146 and K222 are significantly more resistant to scrapie, even with just one copy. Testing for these genetic markers is currently available at UC Davis, with plans for other labs to begin offering the testing. The testing costs $30 per animal and will identify animals that carry one or both copies of each allele.
Further success of the National Scrapie Eradication Program depends on producers keeping records of animal purchases and sales for at least five years. Documenting the transit of these animals allows the USDA to trace positive animals to their herd or flock of origin. Official scrapie ID on all animals entering or leaving a herd will ensure that disease traceability is possible. The tags are meant to identify animals within a specific herd. Keeping appropriate records and not sharing tags with other producers will help ensure that disease prevalence continues to decline.
Scrapie is a serious disease that can negatively impact sheep and goat production. Following the National Scrapie Eradication Program guidelines will help eradicate the disease from the United States. Beginning to use scrapie resistance testing in goats, especially for breeding animals, is a tool that can further reduce the risk of animals contracting the disease. Though not part of the national program, these tests are reliable indicators of an animal’s ability to resist scrapie infection. In addition to following these recommendations, remembering to test animals that pass on the farm, especially those exhibiting neurologic signs, can further help to remove scrapie from the sheep and goat population.